Lua最长重复子串：二分长度加哈希查重

local function hasRepeat(s, L)
    local seen = {}
    for i = 1, #s - L + 1 do
        local seg = s:sub(i, i + L - 1)
        if seen[seg] then return true end
        seen[seg] = true
    end
    return false
end

local function longestRepeat(s)
    local lo, hi, best = 1, #s - 1, 0
    while lo <= hi do
        local mid = math.floor((lo + hi) / 2)
        if hasRepeat(s, mid) then
            best = mid
            lo = mid + 1
        else
            hi = mid - 1
        end
    end
    return best
end
local p = getplayerbyname("rep01")
sendmsg(p, 1, "最长重复片段 "
    .. longestRepeat("abcabcab") .. " 位")